Retting process for textile fibers.



ACHILLE VAN STEENKISTE, OF, BRUSSELS, BELGIUM.

Specification of Letters Patent.

RETTING PROCESS FOR TEXTILE FIBERS.

Patented April 3, 1906.

Original application filed February 14, 1902, Serial No. 94,069. Divided and this application filed August 3 1904. Serial No. 219,41 1.

To all whom it may concern:

Be it known that I, AemLLE VAN STEEN- KISTE, manufacturer, a subject of the King of Belgium, residing at 286 Rue du Progrs, Brussels, in the Kingdom of Belgium, have invented new and useful Improvements in or Relating to Betting Processes for Textile Fibers, (for which patents have been filed in Belgium, August 2, 1901, Patent No. 157,966; in France, December 26, 1901, Patent No. 317,282; in Great Britain, January 3, 1902, Patent No. 244/02; in Germary, January 8, 1902, Patent No. 143,126; in Russia, January 12, 1902, Certificate No. 16,114; in Hungary, January 14, 1902, Patent No.v 24,367; in Austria, January 21, 1902, Certificate No. 23,166; and in Ital ,January 30, 1902, Patent No. 152,203,) of which the following is a full, clear, and exact description.

The retting process which forms the subject of this invention is a divisional application of an application filed by me on the 14th day of February, 1902, Serial No. 94,069, and differs, essentially,from the process previously practiced, as the dry steam never comes into immediate contact with the fibers, which would result in depriving them of all their flexibility.

My new process comprises admission of steam and continuous rotary motion of the textile fibers, so that steam never comes into contact with a single dry fiber. The pectic acid gets therefore uniformly distributed in the fiber, it adheres to them in a more eflicient manner than is the case when the retting is effected in a river, so that after a shorter operation a supple flax of beautiful appearance is obtained. My new process has therefore considerable advantage over the processes hitherto known, both as regards the quality of the linen and the facility and rapidity of the operation.

The rocess chiefl consists in the treatment 0 the flax, to e retted by water and steam at different temperatures and at different pressures, according to the description given hcreinaften,

For carrying out the process according to this invention an apparatus is used consisting chiefly of a tight -closing boiler, in which is a drum rovided with compartments and capable of fieing rotated about a spindle. The flax to be retted is placed in the boiler, the bunches being placed in the longitudinal direction.

The drum or the rotting-basket must be capable of intermittently rotating, so as to turn' flax at regular intervals, moisten its fibers uniformly during determined time periods, this being an essential condition for arriving at the desired result. 7

As is well known, it is impossible to render soluble and eliminate the pectin except by the application of suitable temperature. All processes hitherto suggested for rapid artificial retting, according to which water or hot steam were used, were unsuccessful, because the temperature of water or steam used was either too low or too high, so that the fibers always retained a portion of the pectin in the shape of an insoluble substance which could not be removed therefrom.

According to this invention, the pectinis rendered soluble and removed in two operations, which must be kept distinctly separate from each other, in the following manner: First of all,'the flax to be retted is introduced into the drum in longitudinal direction and the boiler is closed in a tight manner. Then by means of a pipe arranged under a perforated false bottom water of ordinary temperature and in sufficient quantity to almost com letely cover the flax is introduced into the oiler. Steam at about 100 centigrade at the pressure of approximately one atmosphere is then admitted through another pipe, the water thus being heated to about or centigrade. Under the action of hot water, the temperature of which is maintained nearly for an hour at the given value, the pectin is converted into soluble pectic or parapectic acid which owing to its gelatinous consistency continues to adhere to the fibers, while all other solublesubstances and constituent elements are removed through a drain-cock. At the end of this operation there remains in the boiler only parapectic acid with which only the fibers are impregnated, the gelatinous parapectic acid containing all its pectic acid that remained insoluble. Then in order to lixiviate the remaining ectin and to discharge it with the water of ixiviation before the solution of pectic acid takes place in order to enable the pectic acid to spread uniformly over. the fibers a bath similar to that hereinbefore described is utilized, and a current of steamat a pressure of about three atmospheres is admitted into it.

During the first half-hour, during which the water becomes heated, all, the pectin becomes dissolved and there only remains on the fibers insoluble pectic acid, which is dis solved in an absolutely complete and 'unicaping with it.

In order to impart to the flax the desired flexibility, so as to make it capable of resisting stains, a suitable quantitysay ten per cent.of glycerin or of sulforicinate of sodium or of any other softening substances that do away with the necessity of lubricating can be added to the bath in uestion. The water and steam are then disc arged, the flax thus being washed. The whole operation does not last more than two hours, and the fibers get an absolutely correct color and consistency.

If it is desired to apply the process to other textile fibers of less delicate quality than that r .of flax-such as, for instance, hemp, jute &c.-the operation of the second bath coul be repeated twice or more with a current of high-pressure steam, according to the proportion and quality of pectin contained in the fibers in question.

solved, the latter operation bein bath, the water of which has been raised to a temperature of about 95 to 100 centi'grade by the introduction of steam, for the purpose of converting the pectin into para ectic acid, the operation in uestion being fol owed by the passage throug a second bath maintained at a pressure of three atmospheres by the introduction of a current of steam, 'for the purpose of, dissolving and discharging parapectic acid and of spreading uniformly throughout the fibers pectic acid finally disefiected, if desired with the addition of substances intend ed to soften and to render the fibers supple, such as for instance glycerin or sulforicimate of sodium.

The foregoing specification signed this 17th day of June, 1904.

ACHILLEVAN s EENKisTE.

In presence of- R. K001i, GREGORY 'PHELAN. 

